Automatic firearm



Sept. 21, 1937. M. A. BROWNING lAUTOMATIC -FIREARM Filed April l0, 1934 4 Sheets-Sheet 1 I Sept. 2l, 1937. M. A. BRowNlNG AUTOMATIC FIREAHM Filed April l0, 1934 4 Sheets-Sheet 2 Sept. 21, 1937. M. A. BRowNlNG AUTOMATIC FIREARM Filed April 10, -1934 4 Sheets-Sheet 3 Sept. 2E, 1937. M. A. BROWNING AUTOMATIC FIREARM r ...E l ...L

Patented Sept. 21, 1937 uNiTED STATES PATENT oFFicE 2,093,104 AUTOMATIC FIREABM Marriner A. Browning, Ogden, Utah, assigner to J. M.- & M. S. Browning Company, Ogden, Utah, a corporation of Utah Application April 10, 1934, serial No. 719,862

13 Claims.

The general object of the present invention is. to pro-vide an automatic firearm or machine gun' larly applicable to a gun of the gas operated type,

the barrel being normally rigidly connected with the breach casing.

10 In accordance with the invention the cartridge feed channel is below the barrel and the cartridges are fed by means of a slide positioned below the feed channel and operated by the gas actuated operating slide. The operating slide. and

l also. the cartridge feed slide are preferably removable.

Further in accordance with the invention I provide an improvedy means for transferring the cartridges from the feed channel to the chamber zo of the barrel.`

In the accompanying drawings I have shown one embodiment of the invention, but it will be understood thatthe drawings are for illustrative purposes only and are not to be relied uponas ,5 limiting or defining the scope of the invention, the claims forming a part of this specification being relied upon for that purpose.

Of the drawings:

Fig. 1 is a side view of a firearm embodying the 30 invention.

Fig. 2 is an enlarged fragmentary View of the rear portion of the firearm, this View being partly a side View and partly a longitudinal sectional view.

55 Fig. 3 is a view similar to Fig. 2, but showing the parts in different relative positions.

Fig. -4 is an enlarged fragmentary view of thev Afront portion of the firearm, this .view- .being partly a side view and partly a longitudinal sec- 40 tional view;

Fig. 5 is a view similar to Fig. 4, but showing the parts in different relative positions.

Fig. 6 is a fragmentary perspective view of the rear portion of the barrel.

,15 Fig. 7 is a transverse sectional View taken along the line 1-1 of Fig. 4.

Fig. 8 is a transverse sectional View taken along the line 3 8 of Fig. 3. Y

Fig.'.9 is a perspective view showing the ex- 50 tractor.

Fig. 10 is an enlarged fragmentary horizontal sectional View taken along the line Ill-I0 of Fig. 1

Fig. l1 is a View similar to Fig. l0, but showing 55 the parts in different relative positions.,

Fig. 1 2 isa plan view of the operating slide, together with a. part of the piston rod.

Fig. 13 is a side view of the parts shown in Fig. 12, this viewbeing partly in section along the line |3-I3 of Fig. 12. 5

Fig. 14 isl a perspective view of the feed slide.

Fig. 15 is a transverse sectional view taken along the line |5l.5 of Fig. 11.

Fig. 16 is a view taken along -the line |6-I6 of Fig.'10 and showing in detail the extractor and 10 ythe cam mechanism which operates it. In this view the extractor, the pressure lever .for the extractor and the cam mechanism are shown in full lines and all other parts are shown in dotand-dashlines.

Figs. 17, 18 and 19 are views similar to Fig. 16, but showing the parts in different relative positions. 1

Figs. 20 and 21 are fragmentary views similar to portions of Figs. 2 and 3, but showing the re- 20 `,tarding mechanism parts in different relative positions'.

Fig. 22 is an enlarged fragmentary plan view taken along the line 22-212 of Fig. 21.

Fig. 23 is an enlarged fragmentary longitudinal 25 sectional view taken along the line 23-28 of Fig. 22.

Fig. 24 is a view similar to'Fig. 23, but showing the parts in different relative positions.

Referring to the drawings, I represents as an entirety the main breech casing which is generally rectangular in section as shown in Fig. 8. As shown the casing is formed from a single piece of steel although I do not necessarily limit myself to this integral construction.. 'I'he portion la of 35 the casing is formed to receive the rear end of n a barrel 2. Behind the portion Iil are two main side walls lb, Ib connected near the center by an integral cross member IG. An opening ld is provided at the front of the cross member Ic, 40 which opening is normally closed 'by a pivoted y cover 3 held by a-releasable latch 3a. An opening is provided at the rear` of the cross member, which opening is closed bya plate 4.' The bottom of the casingis normally closed by separate plates 5 and 6. 'I'he rear of the casing is normally closed by a plate 'l flanged 'at its sides and having ribs (not shown) adapted to enter grooves 1a, 1a (see Fig. 10) formed in the side walls lb, i". A suitable latch 1b serves to normally hold the end plate 1 50 in place. Carried by the plate 1 at opposite sides thereof are two brackets 8, 8 carrying handlesQ, 9.

'I'he barrel 2 is preferably detachablyconnect- 1 ed with the casing and has a rear cylindrical por- 05 vtion 2B which fits a cylindrical hole in the portion Ia of the casing. 'Ihe rear end of the barrel isprovided at I with. interrupted external threads adapted to engage similar internal threads formed in the casing. When the barrel is in the position shown in Figs. 2 and 3 it is firmly held in place by the threads. It can be released by being turned through a quarter turn in the clockwise direction' as viewed in Fig. 6. The barrel is normally held in its locked position by means of a pin held by a spring I2. The rear end of thespring is T-shaped and fits a T-shaped groove I3 in the' top of the casing, and a screw I4 normally serves to prevent the spring from moving rearward out of the T-shaped slot. The pin I I can be withdrawn from the hole in the barrel by means of a suitable tool such as the head of a cartridge and then the barrel can be turned in the clockwise direction to disengage the interrupted threads at I0. This permits the barrel to be drawn out in the forward direction. In order to avoid the necessity for using a tool to replace the barrel, the barrel is provided as shown in Figs. 6 and 15 with a longitudinal groove I5 positioned to receive and provide clearance for the pin I I The groove I5 has a beveled surface |59 adjacent its forward end, which surface serves to cam the pin outward when the barrel is moved in the counter-clockwise direction into locking position. As soon as locking position is reached the pin I I snaps into the hole in the barrel, thus firmly locking it.

The barrel 2 may be provided with a series of annular ribs to facilitate cooling, but such ribs are not shown. As already explained the barrel is readily removable, and if excessive heating eventually occurs the gun may be kept in service by removing one barrel and substituting another.

The casing I is provided with an integral extension |e which extends forward underneath the barrel. This extension is hollow and it serves t0 engage and retain Va piston tube I6. The tube I6 is preferably slidable longitudinally with respect to the casing, and its movement is guided in part by a removable pin I1 in the casing extending through a longitudinal slot in the rearward extending portion |68 of the tube. In addition there is preferably a lip I 6b on the tube extension slidably engaging the wall of a recess |8 in the plate 6. At its forward end the tube |6 is connected with and supported by the barrel. Preferably the tube is provided at the topthereof with a projection 9 having a T-slot therein which nts a T-shaped projection on the barrel. With the parts engaged as shown in Figs. 4 and '1, the tube is held in rigid relationship to the barrel, but by moving the tube rearward it is disengaged from the barrel as shown in Fig. 5, thus leaving the barrel free to be turned so that it may be disengaged from the casing in the manner already explained.

The tube |6 is normally held in its forward engaged position by means of two links 2| and 22 which are pivotally connected with each other by a pin 23. Preferably the link 2| is U-shaped in cross section so as to partly surround and enclose the link 22. 'I'he link 2| is pivoted to the A front end of the portion |e of the casing by means of a removable pin 24, and the link 22 is pivoted to the tube I6 by means of a pin 25. A spring pressed latch 26is provided for holding the link 2| in its vupper or normal position. It will be observed that with the parts in the positions shown in Fig. 4 the tube I6 is held in its forward position, the link 2| substantially enclosingthe link 22. When it is desired to move the tube I 8 in the rearward direction the link 2| is disengaged from the latch 26 and the link is moved downward to the position shown in Fig. 5, thus drawing the tube rearward and disengaging the projection I9 from the T-shaped projection on the barrel.

Longitudinally movable along the bottom of the main casing is an operating slide 21, this slide being connectedwith a piston rod 28 and a piston 29 positioned Within the piston tube I6. As shown the piston rod is connected With the slide by means of a pin 3|). Preferably the piston 29 is formed integrally with the rod arid consists tube |6,being held in place by `threads; and the piston 29 accurately fits the said cylinder. A series of registering gas holes connect the bore oi' the barrel 2 with the interior of the cylinder 3| in order that a portion of the gases of explosion may enter the cylinder and act upon the piston 29 to force it rearward.

For returning the slide in the forward direction after having been moved rearward by the piston and piston rod, there is provided an action spring 32 supported upon and guided by a rod 33. Preferably the spring 32 and rod 33 extend into a hollow buer 34 carried by the rear plate 1. The spring at its rear end abuts against a head 35 detachably secured in place in the buffer.

' sufficiently wide at the left hand side ofthe gun to permit the entry of cartridges, but preferably its width is only slightly greater than the length of the cartridges. At the right hand side the feed channel is much narrower, being only wide enough to permit the exit of the canvas belt which'carries the cartridges. 'I'he before-mentioned plate 6 is formed with upward extensions 6a, 6*al which have guide openings therein to receive and guide the slide 21. The said plate 6 is also provided with grooves 38, 38 for guiding a transversely and rectilinearly movable feed slide 39. The side walls of the breech casing have apertures therein cooperating with the grooves 38 to form an unobstructed feed slide guide channel. The feed slide with its appurtenances is insome respects similar to that disclosed in Patent No. 1,293,021 toJohn M. Browning.

'I'he longitudinally movable operating slide and the transversely movable feed slide have cooperating elements which enable the former to operate the latter.' Preferably, these cooperating elements comprise a cam path on one slide and a cooperating cam follower on the other slide.

While the details of arrangement may be varied I prefer to locate the feed slide 39 below the operating slide 21. At the bottom of the slide 21 there is provided a cam path which is preferably in the form of a cam groove 40 cut in the bottom surface of the slide. At least a portion of this groove 40 is inclined with reas possible so as to obtain maximur'nspeed of operation and to reduce the total weight of the firearm. By forming the cam groove 40 in the operating slide and providing the` feed slide with the pin 4| the Width of the feed slide can be reduced to that necessary for proper feeding of the cartridges. As shown, the feed slide is substantially less in width than the cartridge feed channel 31. When the slide 21 is in its rearmost position as shown in Fig. 10 the feed slide 39 is at the left hand limit of its movement; and when the operating slide 21 is in its forward position as shown in Fig. 11 the feed slide is at the right hand limit of its movement. Thus longitudinal movement of the operating slide 21 serves to cause transverse movement of the feed slide 39. Carried by the feed slide 39 is a pivoted pawl 42 which is adapted to engage the successive cartridges of the belt A to feed the saidbelt from left to right during the 'movement of the feed slide from left to right. The pawl 42 is provided with a tail piece 42a which underlies and helps to support the cartridge which is engaged. During movement from right to. left the pawl 42 passes under the next following ,cartridge and then snaps upward in position to engage it. A pawl 43 carried by the casing serves to prevent outward movement of the feed belt.

Preferably the slide 21 and the parts associated therewith are removable from the rearm at the rear thereof. To effect such removal it is necessary rst to remove the spring 32 and the rod 33 and to then remove the end plate 1 with the parts carried thereby. The slide is then substantially `free to be withdrawn in the rearward direction except for the fact that the pin 4| is engaged in the cam groove 40. In order to permit the rearward removal of the camslide, provision is made to permit the cam engaging means on the feed slide, that is, the pin 4|, to bedisengaged from the cam path, that is, from the groove 40. This disengagementV may be effected in different Ways, but I have shown .the groove '40 as having a transverselyunobstructed portion or opening 44. During the normal reciprocation of the slide 21 the unobstructed portion or opening 44 does not come into register with the pin 4|, but by moving the slide rearward slightly beyond its normal limit of 'movement the opening 44 is brought into register with the pin 4|, thus permitting the pin and Vslide to be moved transversely sufilciently to be disengaged from the cam groove 40. With the pin 4| thus disengaged from the cam groove the slide can be readily withdrawn rearward.

Preferably the feed slide 39 is entirely removable from the firearm, being normally held in place solely by reason of the engagement of the pin 4| with the'groove 40. So long as the operating slide 21 remains within its normal range of movement the feed slide 39 is held and removal thereof is prevented. However, when the operating slide is moved sufciently to bring the opening 44 into register with the pin 4| the feed slide can then be entirely removed from the rearm. In order to prevent the slide 39 from coming out accidentally or when not so desired during removal of the slide 21, there is preferably provided a spring 39a secured .to the bottom of the slide. This spring will engage with the shoulder at 6b, and will thus resist outward movement of the slide. However, by applying a slight pressure the resistance of the spring can be overcome and the slide can be removed.

The firearm is provided with a reciprocating breech bolt 45 which is guided. between the side walls lb, |b of the casing. The breech bolt is operated and controlled by mechanism operated by the slide 21, this vmechanism being similar to.

that disclosed in Patent No. 1,293,022 to John M.

Browning. As shown in Fig. 3 the breech bolt 45 is connected with the slide 21 by means of two links 46 and 41 pivotally connected with each other at 48. The link 46 is pivotally connected with the breech bolt at 494 and the link 41 is pivotally connected with the slide at 50. When the slide 21 is in its rear position as shown in Fig. 3, the two links 46 and 41 are held substantially in alinement in the relative positions shown. A lug 41a on the link 41 engages the link 46 to prevent downward movement beyond the position shown.

,When the slide 21 moves forward under the inuence of the action spring 32 the two links 46 and 414 and the breech bolt 45 move in unison with ituntil the breech bolt nearly reaches its forward position, the link 46 being then approximately in register with the opening I@I in the top wall of the casing. At or about the time that the link comes into register with the opening the curved portion 46b of the link 46 engages two cams projecting inward from the respective side walls Ib, Ib of the casing. In the drawings only the cam on the lefthand side is clearly shown, but it will be understood thatthere is a similar cam o-n the right hand side. These cams 5| cooperate with the curved portion 46b of the link 46 to force the link upward into the opening Id, the rear end portion of the link abutting against the rear wall of the opening as clearly shown in Fig. 2. In the meantime the slide 21 has continued its forward movement, thus bringing the link 41 into a, substantially upright position. With the parts in the position shown and described, the breech bolt is firmly locked in its forward or breeched position and is well adapted to resist the recoil action incident to ring. Following ilring the slide 21 is moved rearward by the action of the gases of explosion in the manner already described, the link 41 serving rst to draw the link 46 downward out of locking position and then to move the link46 and also theY bolt rearward to the positions shown inFig. 3.

Reference has already been made to the fact that the slide 21 can beremoved through the rear of the casing. It will be understood that the breech bolt 45y andthe links 46 and 41 are similarly removable, all of these parts-being removable as a unit. v

A firearm incorporating the present invention is intended to be used with cartridges having annular grooves in the heads thereof, and the front end o-f the breech bolt is provided with vertical ribs 52, 53 which cooperate to form a Vertical groove for receiving and lretaining the heads of the cartridges. forward position as shown in Fig. 2 the head of the cartridge which is in central positionin the When the Abreech bolt is' inits feed channel 31 is vertically below the groove in with the chamber in the barrel. i movement continues the cartridge is pushed into it into proper relationship to the breech bolt there y rearward and forward as the breech bolt moves;

The extractor 54 is provided with a transversely extending tooth 56 which is so shaped and positioned as to enter the groove in the ,cartridge when the breech bolt and the extractor are in their forward positions as shown in Fig. 2. For pressing the forward end of the extractor upward so as to holdthe tooth 56 in rm engagement with the cartridge, there is provided a pressure lever 51 pivoted to the breech bolt at 58 and engaging at itsforward end with the extractor. A coil spring 59 tends to move the pressure lever 51 in the counter-clockwise direction, thus pressing the forward end of the extractor upward.

A suitable cam. mechanism is provided for controlling and guiding the relative movements vof the extractor and preferably this mechanism is located at the left side of the firearm. For convenience of construction the left side wall Ib is cut away to provide an opening 60 as shown in Fig. 3 and this opening is covered. by a plate 6|, shown in Figs. 10 and 11. The cam mechanism to be now described is carried by the plate 6l and projects inward through the opening 60.

The extractor 54 is provided with a pin 62 which projects toward the left and which serves as a means for controlling the upward and downward movements of the extractor. When the breech bolt moves rearward from the position shown in Fig. 2 the extractor 54 withdraws the cartridge with which it is engaged and the extractor is moved upward by the lever 51. Thereafter as shown in Fig. 16 the pin 62 engages a cam surface 63 on the plate 6I which forces the pin upward and thus causes continued upward movement of the extractor. Thus the cartridge is moved not only rearward but also upward. Continued rearward movement brings the parts into the relative positions shown in'Fig. 3, the pin 62 being retained between two cam walls.

The cam plate 6| carries a pivoted cam member 64 which is normally spring pressed to the position shown in Figs. 3, 17 and 19. However, the pin 62 in moving rearward passes under the rear portion of the cam member 64 and lifts it as shown in Fig. 16. When the parts move forward from the position shown in Fig. 3, the pin 62 Amoves along* the top of the cam member 64 as shown in Fig. 17, thus further lifting the cartridge so that it is brought into exact alinement As forward the chamber in the barrel as shown in Figs. 18 and 2.

When the cartridge has been sufciently entered in the chamber to be retained thereby, the extractor 54 is withdrawn from it, the pin 62 engaging the cam surface 65 as shown in Fig. 18 and being pushed downward. As forward movement continues to the position shown in Fig. 19, the extractor is moved still further downward, the pin 62 being disengaged f rom the cam members and the extractor being held directly by the cam surface 68. As the extractor reaches the position shown in Fig. 2, the tooth 56 engages the next cartridge and the parts are in positionsv for a repetition of the loading operation which has just been described.

As shown in Fig. 8 a second extractor 69 is provided immediately above the cartridge shell retaining rib 53. This extractor 69 is so shaped and positioned that it is entered in the groove in the cartridge shell when the cartridge is in ringposition. The. extractor 69 is resiliently mounted, being carried by a spring 10, as shown in Fig. 2. The rear portion lof the barrel is provided with a notch 1I into which the extractor 69projects when in its forward position. With the parts in the position shown in Fig. 2 ring is automatically effected by means tobe presently described, and the parts again-move in the rearward direction. The shell of the cartridge which has just been red is held by the extractor 69 and is thus drawn rearward as the bolt moves rearward.

Mounted in a. groove in the bolt 45 at the left side thereof is an ejector 12, normally held by a spring 13 in its rearward position with respect to the bolt, as shown in Fig. 11. 'I'he ejector' 12 is connected to the bolt by means of a stud on the bolt extending through aslot in the eector.

Carried by the casing at the left side thereof is a pin 14 which is in position to engage a `shoulder 12a on the ejector.' Just before the breech bolt reaches its extreme rearward position the pin 14 engages the shoulder 12' and moves the ejector relatively forward with respect to the bolt as shown in Fig. 10, thus throwing the cartridge shell toward the right to the position B. An ejection opening 16 is provided in Athe right Wall of the casing and theshell is thus thrown out through this ejection opening.

Preferably the pin 14 is carried by a spring 11 secured to the left side wall of the casing. This spring mounting for the pin 14 enables the pin to be withdrawn so ras to avoid interference when the breech bolt and other parts are to be removed through the rear of the casing, The spring has the further advantage of providing a limited resilience which avoids excessive shock incident to the ejection operation.

It has already been stated that with the breech bolt in its forward position as shown in Fig. 2 the extractor- 69 projects into the notch 1I in the barrel. This would prevent removal of the barrel and no attempt should be made to remove it with the parts in this position. Ordinarily and preferably when the tubev I6 is to be moved rearward as shown in Fig. 5 preliminarily to removing the barrel, the slide 21 and the piston rod 28 are in their rearward positions as shown in the same gure. In the event, however, that the slide and the piston rod are permitted to remain in their forward positions as shown in Fig. 4, Aa shoulder llic on the tube I6 engages` the forward end of the slide 21, thus causing the slide to move rearward as the tube moves.

This rearward movement of the slide serves to move the breech bolt 45 rearward to a suilicient extent to withdraw the extractor 69 from the barrel notch 1I. 'Ihis prevents any injury to the extractor 69, even though the slide and bolt have not been moved to their rearward positions prior to the operations incident to the removal of the barrel.

Mounted in a hole in the breech bolt 45 is a firing pin 18 capable of limited longitudinal movement and having an enlarged head 18a at the rear. The ring pin is provided with a lug 19 which projects upward through a suitable slot in the and serves as alcam surface* to engage the lug 19 and thus move the firing pin 18 relatively rearward during rearward movement of the breech bolt. The lug 19 serves to positively prevent the iiring pin from coming into engagement with the cartridge except when the breech bolt is in its forward position as shown in Fig. 2.

For actuating the ring pin 18 there is provided a hammer 8| pivoted at 82 in a recess in the top plate 4. Fig. 3 shows the hammer in cocked position, it being so held by a sear 83 pivoted to the plate 4 at 84 and engaging a shoulder 8| extending transversely of the hammer. The scar 83 is biased toward its engaged position by a spring pressed plunger 85. The hammer is biased toward its firing position by means of a link 86 pivoted to the hammer at 81. The link is supported and guided at the rear by a lug 88 through which it extends. A spring 89 surrounds the link and abuts against the lug 88. The forward end of the spring abuts against a shoulder on the link. f

The hammer is cocked by engagement with the slide 21 and its associated parts as they move rearward from the position shown in Fig. 2 to the position shown in Fig. 3. To facilitate cooking the slide 21 is provided with two upward projecting lugs 90, 90 which initially engage the hammer to start the cocking movement thereof. Subsequently the hammer is engaged by the upward extension 46B on the link 46 which serves to move it to its fully cocked position as shown in Fig. 3.

In orderthat the hammer, when released, may

actuate the firing pin there is provided an intermediate striker 9| carried by the link 41. This striker is in the form of a rod slidably mounted in a hole in the link and having longitudinal movement therein, such movement being limited by a pin 92 extendingl transversely of the link and extending through a notch in the rod or striker. The relationship of the parts is such that when the breech bolt is in its forward position the striker 9| is in engagement with the enlarged rear end portion 18a of the ring pin 18. When the hammer is released inthe manner to be presently described it moves from the position shown in-Fig. 3 to the position shown in Fig. 2, engaging the striker and driving it forward to actuate the firing pin and to thus cause the cartridge to be red.

The lower right hand portion of the sear 83 is cut away to provide a notch for a sear operating lever 93. This lever is clearly shown in Fig. 2, but a part of it is omitted from Fig. 3 in order that the sear itself may be more clearly shown. The operating lever 93 is preferably pivoted coaxially with the hammer 8| 4and the forward end thereof is in engagement with the downward facing top wall of the before-menthe forward portion ofthe lever 93, thus forcing,

the said forward portion upward and movingthe sear 83 in the counter-clockwise direction so as to release the hammer.

For holding the slide 21 in its rear position as shown in Fig. 3 there is provided a second through an opening in the plate and is adapted t'o engage the sear 95. A spring pressed plunger 98'tends to hold the trigger in its rearward inoperative position.

In initially loading the gun in order to start ring it is fordinarily necessary to operate the mechanism of the gun by hand in order to withdraw the first cartridge from the belt and transfer it into the position shown in Fig. 3. For this purpose there is provided ahandle 99 extending through a slot |00 in the right side wall of the casing and fitting a hole |0| in the'slide 21. The slot |00 is enlarged at its rear end and the handle 99 is sofonned that it can be removed only when in register with the enlarged rear end of the slot.

When the trigger 91 is pressed forward the sear 95 is disengaged from the slide 21 and the slide moves forward, causing the links 46 and 41 and the breechbolt 45 to assume the positions shown in Fig. 2. vWhen these positions are reached the projection 94 on the slide 21 releases the hammer 8| in the manner already described, thus actuating the firing pin and causing ring. Thereupon the gases of explosion enter the cylinder 3| and drive the piston 29 rearward, thus moving the slide 21 rearward and causing the various parts of the-gun to assume the relative positions shown in Fig. 3. During this rearward movement a. new cartridge is extracted from the belt and the shell of the exploded cartridge is ejected in the manner already described. If, in the meantime, the trigger 91 has been released and permitted to resume its normal position, the slide is caught and held by the Sear 95 and no further ring takes place. If, however, the trigger 91 is held in its forward ring position the partsv immediately again move forward to the firing position shown in Fig. 2 and firing again occurs. Thus volleyiiring may be continuedv so long as the trigger 91 is held and so long as the supply of cartridges in the belt is not exhausted.

In addition to the parts already described the gun may also be providedfwith a means for retarding the rate of fire. This means may be included or omitted as desired.

As shown, particularly in Figs. 22, 23 land 24, there is provided an auxiliary sear |02 mounted coaxially with the sear 83 and biased' toward its engaged position by a spring |03'. The sear`|02J is positioned at the left side of the gun and is adapted to engage the same shoulder 8|a in the l' hammer that is engaged by the sear 83. For

disengaging the sear |02 from the shoulder 8|EL there is provided a slide |04 at the left side of the gun, this slide being guided in'part by the pivot pin at 82 and in part by a pinv |05 projecting inward from the left side of the recess in the--top platev 4. When fthe slide ,|04 is in its rearward position as shown in Fig. 24 the scar |02 engages the shoulder 8|a and prevents -move- :nent of the hammer even though the sear 83 be released in the manner heretofore described.

If the slide |04 be moved forward to the position shown in Fig. 23 an extension |04a on the slide engages the sear to disengage it and thus release the hammer.

Secured to-the top plate 4 is a bracket |06, this bracket being U-shaped and carrying two pivot pins |069 and |01. Mounted on the pivot pin |06a is a ratchet wheel 08 and an escapement Wheel |09, these two wheels being connected together for movement in unison. Mounted on the pivot pin |01 is an escapement weight |I0 having teeth thereon which engage the teeth on the wheel |09. 'Ihe teeth on the escapement weight are so related to the teeth on the wheel that the weight is forced to oscillate as the wheel is turned. 'I'hus the weight offers resistance to the turning of the wheel.

Pivotally mounted at I'I is a lever I I2 which is biased for movement in the counter-clockwise direction by means of a spring II3. Pivotally connected at |4 to the lever I2 is a ratchet arm I5 having teeth thereon adapted to engage with the teeth of the ratchet wheel |08. A spring IIB serves to bias the arm I5 in the clockwise direction, thus tending to hold it in engagement with the wheel. The lever |2 is positioned at the left side of the casing and is adapted'to be engaged and reset by a cam surface I I1 on the slide 21. Thus when the slide moves rearward the lever ||2 is moved or reset in the clockwise direction to the position shown in Fig. 2. In so moving the teeth on the arm ||5 may snap over the teeth on the wheel |08 without causing the wheel to rotate.

It will be seen that the lever ||2 after having been moved by the cam I1 to the position shown in Fig. 2, tends to move in the counter-clockwise direction, but it can so move only by causing corresponding rotation of the ratchet wheel |08. The ratchet wheel is restrained from rapid movement by reason of its connection with the escapement wheel |09. Thus the lever ||2 is permitted to move in the counter-clockwise direction, but only at a relatively slow rate determined by the action of the escapement weight ||0.

'I'he lever |I2 is provided with a forward extension I2a which is adapted to engage the rear edge of the slide |04; 'I'hus as the lever moves relatively slowly in the counter-clockwise direction, the extension ||2f7L engages the slide |04 so that the slide is moved forward to release the sear |02. Fig. 24 shows the extension ||2EL just coming into engagement with the slide, the slide, however, not yet having been moved.

From the foregoing description it will be apparent that when the main operating slide 21 moves rearward to the position shown in Fig. 3, the lever I2 is moved in the clockwise direction to the position shown in the same figure. If the trigger 91 is maintained in its depressed position theslide 21 with its associated parts immediately moves forward to the position shown in Figs 2 and 20, thus releasing the main sear 83 in the manner already described. Firing, however, does not immediately occur for the reason that the hammer is still held by the auxiliary sear |02. However, as soon as the cam surface I|1 on the slide 21 moves out of the way of the lever ||2 the said lever starts to move relatively slowly in the counter-clockwise direction, the extension ||2EL thereof eventually engaging the slide |04 as shown in Fig. 24. The slide |04 is then pushed forward to release the sear |02 and thus permits the hammer to move and causeV firing as shown in Fig. 21. With this retarding mechanism in use the rate of fire may be very much less than it otherwise would be, the amount of decrease in the rate being in large measure dependent upon the size of the escapement weight I I0.

It will be observed that when the retarding mechanism is used the main sear 83 normally has no control of the ring, but the said sear nevertheless serves as a safety means to prevent premature release of the hammer in the event of any jamming or malfunctioning of the gun. The sear 83 prevents release of the hammer before the breech bolt reaches its forward locked position.

The retarding mechanism serves not only to decrease the rate of nre but also to increase accuracy. The momentary delay between the closing of the breech and the ring of the cartridge permits vibrations to expend themselves so that the gun is in a static condition at the instant of iir- In order that the retarding mechanism may be rendered inoperative when not required, there is preferably provided a transverse shaft or pin I I8 adapted to be oscillated by means of a lever ||9 on the exterior of the casing. Secured to the pin I8 is a` finger |20 which is adapted to engage the lever |I2, as shown in Fig. 23, to maintain it in. its rearward or inoperative position. Associated with the finger is a projection |2| which engages an extension |Il4b on the slide |04 to hold the slide in its forward position and to thus hold the sear |02 in its inoperative position, as also shown in Fig. 23. With the parts in this position the retarding mechanism is entirely inoperative and the action of the gun is exactly the same as it would be if the said mechanism were not provided.

By moving the lever I|9 in the counter-clockwise direction the nger |20 and the projection 2| can be moved to the positions shown in Fig. 24, thus freeing the retarding mechanism and permitting it to operate in the manner which has already been fully described.

I do not claim as a part of the present inven- March 19, 1935, as a' division of this present apv plication.

What I claim is:

1. In an automatic firearm, the combination of a barrel, a breech casing carrying the barrel and having a transverse cartridge feed channel therein immediately below the rear portion of the barrel, the said feed channel being closed at the front and having a width only slightly greater than the length of the cartridges, a movable breech bolt in the casing,v an operating slide .below the feed channel automatically movable rearward upon ring connected with the breech bolt to move the same and having a cam path at least a part of which is inclined with respect to the direction of movement, a transversely and rectilinearly movable feed slide below 'the feed channel and having a width less than that of said feed channel, means on the feed slide engaging the cam path of the operating slide and thus serving to transversely move the feed slide, and means for withdrawing the cartridges rearward from the feed channel and lifting them upward into alignment with the chamber in said barrel.

2. An automatic rearm comprising in comtion the features of construction which facilitate i automatically movable rearward upon firing connected with the breech bolt to move the same, a transversely movable feed slide below the operating slide, means on the operating slide and on l the feed slide having cooperating elements normally. serving to enable the former tooperate the latter, and means for withdrawing the cartridges rearward from the feed channel and lifting them upward into alignment with the chamber in said l barrel.

3. An automaticlfirearm comprising in com-- bination, a barrel, a breech casing carrying the barrel and having a transverse cartridge feed channel therein immediately below the rear por- 20 tion of the barrel, a movable breech bolt in the casing, an operating slide below the feed channel automatically movable rearward upon ring connected with the breech bolt to move the same and having atthe bottom thereof a cam path 25 at least a part of which is inclined with respect to the direction vof movement, a transversely movable feed slide below the operating slide, means on the feed slide at the top thereof engaging the cam path of the operating slide and 30 thus serving to transversely move the feed slide,

a pawl on the feed slide partly overlying the operating slide and adapted to engage a cartridge belt in the feed channel, and means for withdrawing the cartridges rearward from the feed channel and lifting them upward into alignment with the chamber in said barrel.

4. An automatic firearm comprising in combination, a barrel, a breech casing carrying the barrel and having a transverse cartridge feed channel therein immediately below the rear portion of the barrel, the said feed channel being closed at the front and having a width only slightly greater than the length of the cartridges,

"a movable breech bolt in the casing, an operating slide below the feed channel automatically movable rearward upon firing connected with the breech bolt to move the same and having at the bottom thereof a cam path at least a part of which is inclined with respect to the direction of movement, a transversely and rectilinearly movable feed slide below the feed channel and having a width less than that of said feed channel, means on the feed slide engaging the cam path at the bottom of the operating slide and thus serving to transversely move the feed slide, and means for withdrawing the cartridges rearward from the feed channel and lifting them upward into alignment with the chamber in said barrel.

5. -The combination in an automatic firearm, of a barrel, a breech casing carrying the barrel and having a transverse cartridge feed channel therein below the rear portion ofl the barrel, a movable breech bolt in the casing, a transversely movable feed slide in thefcasing below the feed channel, an operating slide in thecasing movable rearward upon firing connected with the breech bolt to move the same, means on the operating slide and on the feed slide having cooperating elements normally serving to enable the former to operate the latter, the cooperating elements of the last said means being readily disengageable from 'each other while the operating and feed slides are within the breech casing to thereby permit the operating slide to be removed longitudinally from the casing independently of the feed lslide,and means for withdrawing the cartridges rearward from the feed channel and lifting them upward into alignment with the chamber in said barrel.

6. The combination in an automatic firearm, of a barrel, a breech casing carrying the barrel and having a transverse cartridge feed channel therein immediately below the rear portion of the barrel, a movable breech bolt in the casing, a transversely movable cartridge feed slide below the feed channel, an operating slide below the feed channel and above the feed slide automatically movable rearward upon firing connectedl with the breech bolt to move the same and having at the bottom thereof a cam path at least a part of which is inclinedwith respect to the direction of movement, means on the top of the feed slide normally `engaging the cam path of thev operating slide .and thus normally serving to `operate/the feed slide, the last said means being readily disengageable from `the cam path to permit the operating slide to be removed longitudinally from the casing independently of the feed slide, and means for withdrawing the cartridges rearward from the feed channel and lifting them upward into alignment with the chamber in said barrel.

7. The combination in an automatic firearm, of a barrel, a breech casing carrying the barrel and having a transverse cartridge feed channel therein immediately below the rear portion of the barrel, a movable breech bolt in the casing, a transversely movable cartridgevfeed slide below the feed channel, an operating slide automatically movable rearward upon f'lring connected with the breech bolt to move the same and having a cam path at least a part of which is inclined with respect to the direction of movement and which has a transversely unobstructed portion, means on the feed slide normally engaging the cam path to cause normaltransverse movements of the feed slide, the last said means being readily separable transversely from the cam path when in register with the unobstructed portion thereof to permit the operating slide to be removed longitudinally from the casing independently of the feed slide, and means for Withdrawing the cartridges rearward from the feed channel and lifting them upward intol alignment with the chamber in said barrel.

8. The combination in an automatic firearm, of a barrel, a breech casing carrying the barrel and having a transverse cartridge feed channel therein immediately below the rear portion of the barrel, a movable'breech bolt in the casing, a transversely movable cartridge feed slidebelow the feed channel, a cam path engaging means on the feed slide, an operating slide automatically ,movable rearward upon firing connected with the breech bolt to move the same and having a cam path which engages the said means on the feed slide and atleast a part of which is inclined with respect to the direction of movement of the operating slide so as to cause normal transverse movements of the feed slide, the said cam path serving when the operating slide is within its normal range ofD movement to retain engagement with the engaging means on the bottom of the feed slide and the said cam path being transversely unobstructed at one end to permit disengagement of the said means therefrom whenthe operating slide is in an abnormal position, and means for withdrawing the cartridges rearward from the feed channel and lifting them upward into alignment with the chamber in said barrel.

9. An automatic firearm comprising in combination, a barrel, a breech casing carrying the barrel and having a transverse cartridge feed channel and an unobstructed transverse feed slide guide channel therein below therear portion of the barrel, a movable breech bolt in the casing, a feed slide below the feed channel transversely movable in said feed slide guide channel, an operating slide automatically movable rearward upon firing connected with the breech bolt to move the same, means on the operating slide and on the feed slide having cooperating elements normally serving to enable the former to operate the latter, the cooperating elements of the lastsaid means being readily disengageable from each other to'permit the feed slide to, be transversely removed from the casing, and means for withdrawing the cartridges rearward from the i feed channel and lifting them upward into alignment-with the chamber in said barrel.

10. An automatic firearm comprising in combination, a barrel, a breech casing carrying the barrel and having a transverse cartridge feed channel and an unobstructed transverse feed slide guide channel therein immediately below the rear portionof the barrel, a movable breech 'bolt in the casing, a cartridge feed slide below the feed channel transversely movable in said feed slide guide channel and removable transversely from the casing, an operating slide below the feed channel and above the feed slide automatically movable rearward upon firing connected with the breech bolt to move the same and having at the bottom thereof a cam path at least a part of which is inclined with respect to the direction of movement, means on the top of the feed slide normally engaging the cam path of the operating slide and thus normally serving to operate the feed slide and to prevent transverse re-y moval thereof from the casing, the last said means being readily disengageable from the cam path to permit the feed slide to be transversely removed from the casing, and means for withdrawing the cartridges rearward from the feed channel and lifting them upward into alignment with the chamber in said barrel.

11. An automatic firearm comprising in combination, a barrel, a breech casing carrying the barrel and having a transverse cartridge feed channel therein immediately below the rear portion of the barrel, a movable breech bolt in the casing, a transversely movable cartridge feed slide below the feed channel and removable transversely from the casing, a cam path engaging means on the feed slide, an operating slide automatically movable rearward upon firing connected with the breech bolt to move the same and having a cam path which engages the said means on the feed slide and at least `a part of which is inclined with respect to thedirection of movement of the operating slide so as to cause normal transverse movements of the feed slide, the said cam path serving when the operating slide is within its normal range of movement to prevent transverse removal of the feed slide from the casing and the said cam path being transversely unobstructed at one end to permit such removal when the operating slide is in an abnormal position, and means for withdrawing the cartridges rearward from the feed channel and lifting them upwardfinto alignment with the chamber in said barrel.

12. The combination in an automatic firearm, of a barrel, a breech casing carrying the barrel and having a transverse cartridge feed channel therein, a movable breech bolt in the casing, a transversely movable cartridge feed slide adjacent the feed channel and removable transversely from the casing, 'an operating slide automatically movable rearward upon firing connected with the breech bolt to move the same and having a cam path at least a part of which is inclined with respect to the direction of movement, means on the feed slide normally engaging the cam path of the operating slide and thus normally serving to operate the feed slide and to preventtransverse removal from the casing, the last said means being readily disengageable from the cam .path to permit the feed slide to be transversely removed from the casing, a spring means for resisting removal of the feed slide but adapted to permit such removal when pressure is applied, and means for withdrawing the cartridges rearward from the feed channel and lifting them upward into alignment with the chamber in said barrel.

13. In an automatic firearm, the combination of a barrel, a breech casing carryingthe barrel and having a transverse cartridge feed channel therein below the level ofthe barrel, a breech bolt in the casing automatically movable rearward upon firing, an extractor movable with the bolt. and serving during movements thereof to .extract successive cartridges from the feed channel and to move each of them upward into alinement with the bore of the barrel, cam mechanism on the casing for causing upward and downward movements of the extractor, and a spring pressed lever carried by the breech bolt and engaging the extractor when in the extreme forward position to bias it upward into firm engagement with a cartridge.

MARRINER A. BROWNING. 

